This Small Sensor Can Detect Toxic Gas Before You Even Know You're Breathing It

A small new device could make a big difference in India’s fight against air pollution, especially the ones which you can’t see or smell until it hurts your lungs. Scientists from Bengaluru's Centre for Nano and Soft Matter Sciences (CeNS) have built a small and low-cost sensor that can detect toxic sulfur dioxide (SO2) that can cause asthma, lung damage, and other major breathing difficulties. 

What makes this sensor different?

Even at very low levels, it can pick up on this silent threat, which most commercial sensors can't achieve without pricey, power-hungry setups.  SO2 often comes out of car exhaust, coal-burning power plants, and industrial chimneys.  Even small doses, much smaller than what you would notice, can be bad for you.  Hence, it is crucial to keep a check on it in real time. However, the tech involved until today haven’t been any cheap. This new sensor changes that. 

The scientists built this sensor by combining Nickel oxide (NiO) and neodymium nickelate (NdNiO3) metal oxide.  NiO works like the nose, picking up the gas, and NdNiO3 helps deliver the signal.  This smart combination lets the gadget find SO2 at just 320 parts per billion, which is far more sensitive than many other devices on the market today. 

This sensor is light, easy to operate, and has a traffic light-style alarm system that is easy to see. It has colour coded signals- Green is for safe, Yellow means, Yellow means warning, and Red means danger. This makes it easy to understand this technology by anyone including those who don’t know anything about science. 

The sensor is designed Vishnu G. Nath, a Senior Research Fellow at CeNS who came up with the idea for the device. He was helped by a team of researchers including Dr. Shalini Tomar, Nikhil N. Rao, Dr. Muhammed Safeer Naduvil Kovilakath, Dr. Neena S. John, Dr. Satadeep Bhattacharjee, and Professor Seung-Cheol Lee. The research is published in the journal titled Small. 

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